Dermatology Flashcards
What is chondrodermatitis nodularis helicis?
Painful nodule on the ear
Benign
Management of chondrodermatitis nodularis helicis
Reduce pressure on the ear - foam ear protectors during sleep
cryotherapy, steroid injection, collagen injection
Causes of acanthosis nigricans
T2DM GI cancer Obesity PCOS acromegaly Cushing's disease Hypothyroidism Prader-Willi Combined oral contraception Nicotinic acid
What can be a consequence of long term antibiotic use in acne vulgaris?
gram negative folliculitis
Management of gram negative folliculitis
high dose oral trimethoprim
Why is minocycline no longer used for acne vulgaris?
irreversible pigmentation
What is the difference between scarring and non-scarring alopecia?
Scarring = destruction of hair follicle
Non-scarring = preservation of hair follicle
Causes of scarring alopecia
trauma, burns radiotherapy lichen planus discoid lupus tinea capitis
Causes of non-scarring alopecia
male-pattern baldness iron and zinc deficiency alopecia areata telogen effluvium trichotillomania drugs
What drugs cause allopecia?
cytotoxic drugs carbimazole heparin oral contraceptive pill colchicine
Cause of alopeia areata
Autoimmune hair loss
non-scarring
Features of alopecia areata
Demarcated patches of hair loss
“exclamation mark” hairs
Outcome of alopecia areata
50% patients regrow hair by 1 year
80-90% regrow hair eventually
Treatment for alopecia areata
Topical or intralesoinal steroids
Topical minoxidil
Phototherapy
Wigs
How do antihistamines work?
H1 inhibitors
Examples of sedating antihistamines
Chlorpheniramine
Non-sedating antihistamines
Loratidine
Cetirizine
Medical name for athlete’s foot
Tinea pedis
Management of athlete’s foot
Topical imidazole
Topical terbinafine
How does atopic eruption of pregnancy present?
Ecematous, itchy, red rash
What is the commonest skin disorder in pregnancy?
Atopic eruption of pregnancy
What is melasma?
Hyperpigmented macules in sun exposed areas
Causes of melasma
Pregnancy
combined oral contraceptive pill
hormone replacement therapy
What are milia?
Small benign keratin filled cysts typically found on the face
More common in newborns
What are salmon patches?
Pink, blotchy vascular birthmark on new borns
Fade over a few months
Management of periorificial dermatitis
topical or oral antibiotics
Nail changes seen in psoriasis
Pitting
Oncholysis
Subungual hyperkeratosis
Loss of the nail
What is a keratoacanthoma?
Benign epithelial tumour
Features of a keratoacanthoma
Look like a volcano or crater
Initially smooth dome shaped papule
Becomes crater centrally filled with keratin
Management of keratoacanthoma
Urgent excision as difficult to differentiate clinically from SCC
What is granuloma annulare?
Papular lesion slightly pigmented and depressed centrally
Found on dorsal of hand and feet
Management options for hyperhidrosis
1st line = Topical aluminium chloride
Iontophoresis
Botox
Surgery e.g. endoscopic transthoracic sympathectomy
Causes of onycholysis
Trauma Infection - esp fungal Psoriasis, dermatitis Raynaud's Hyper and hypo thyroidism
How to diagnosis nickel dermatitis?
Skin patch test
Vaccination against primary varicella
Live attenuated vaccine
For healthcare workers who are not already immune and contacts of immunocompromised patients
Shingles vaccine
What type of vaccine is it?
Who gets it?
Live attenuated, sub cut
Patients age 70-79
Management of leukoplakia
Biopsy to exclude squamous cell carcinoma
Regular follow up to check for malignant transformation
When are systemic side effects seen from potent topical steroids?
Applied to >10% body surface areas
How long to use potent steroids for?
8 weeks
How long to use very potent steroids for?
4 weeks
Side effects of topical steroids
Skin atrophy
Striae
Rebound symptoms
Can vitamin D analogues be used long term?
Yes
Effect of vitamin D on the psoriasis plaque
Reduce scale and thickness but not the erythema
Can you use vitamin D analogues for psoriasis in pregnancy?
no
Side effects of dithranol used in psoriasis
Burning
Staining
Side effects of phototherapy
Ageing
Squamous cell skin cancer
Phototherapy for psoriasis
narrow band UVB
photochemotherapy= psoralen + ultraviolet A light (PUVA)
Psoriasis - criteria for non-biological systemic therapy
- Can’t be controlled with topical therapy
- Significant impact on wellbeing
+ ONE OF:
- Psoriasis is extensive
- Localised with significant functional impairment/distress
- Phototherapy ineffective
First line systemic therapy agent for psoriasis
Methotrexate
When is ciclosporin used over methotrexate in psoriasis?
Rapid or short term disease control
Palmoplantar pustulosis
Considering conception (men and women)
Second line systemic therapy agent for psoriasis
ciclosporin
Criteria for biological therapy in psoriasis
Failed trial of methotrexate, ciclosproin and PUVA
Effectiveness of oral retinoids for acne
2/3 have long term remission or cure
Side effects of oral retinoids
Teratogen Dry skin, eyes, lips/mouth Low mood Raised triglycerides Hair thinning Nose bleeds Intracranial hypertension Photosensitivity
What is the most common side effect of oral retinoids?
Dry skin, eyes, lips and mouth
Why should you not combine oral retinoids with tetracyclines?
both increase the risk of intracranial hypertension
Causes of erythema nodosum
Infection = strep, TB Sarcoidosis IBD Behcet's Malignancy/lymphoma Drugs = penicillin, sulphonamides, contraceptive pill Pregnancy
Drug causes of urticaria
Aspirin
Penicillins
NSAIDs
Opiates
Management of urticaria
Non-sedating antihistamines
Prednisolone in severe or resistent cases
Which is the most common type of contact dermatitis?
Irritant contact
Irritant contact dermatitis - causes
Detergents
Cement
Irritant contact dermatitis - presentation
On the hands
Erythema typical
Crusting/vesicles rare
Allergic contact dermatitis - causes
Hair dyes
Allergic contact dermatitis - presentaiton
Acute weeping eczema
Which type of skin cancer tends to be found in scar tissue?
Squamous cell carcinoma
Spider naevi associations
Liver disease
Pregnancy
Combined oral contraceptive pill
Polymorphic eruption of pregnancy - features
Generally third trimester
Pruritic eruption
Lesions in abdominal striae
Polymorphic eruption of pregnancy - management
Emollients
Mild potency topical steroids
Oral steroids
Pemphigoid gestationis - features
Pruritic blistering lesions
Peri-umbilical region then spreading
2nd and 3rd trimester
Pemphigoid gestationis - management
oral corticosteroids
What is hirsutism?
Androgen dependent hair growth in women
What is hypertrichosis?
Androgen independent hair growth
Causes of hirsutism
PCOS Cushing's Congential adrenal hyperplasia Androgen therapy Obesity Adrenal tumour Androgen secreting ovarian tumour Phenytoin Corticosteroids
Most common cause of hirsutism
PCOS
How is hirsutism assessed?
Ferriman-Gallwey scoring system
Management of hirsutism
Weight loss
Cosmetic techniques waxing/bleaching
Oral contraceptive pill
For facial hirsutism - topical eflornithine
Causes of hypertrichosis
Drugs = minoxidil, ciclosporin, diazoxide
Congenital
Porphyria cutanea tarda
Anorexia nervosa
Cause of eczema herpeticum
Herpes simplex 1 or 2
Management of eczema herpeticum
Admit for IV aciclovir
Which burns to refer to secondary care?
Deep and full thickness
Superficial burns >3% TBSA in adults or 2% in children
Superficial burns involving face hands perineum genitals or any flexure
Circumferential burns
Inhalation injury
Electrical or chemical burn
Suspicion of non-accidental injury
Features of discoid eczema
Round or oval plaques
Extremely itchy
On the extremities
What is 1 finger tip unit?
0.5g
Sufficient to treat a skin area about twice that of a flat adult hand
Example of a mild potency steroid
Hydrocortisone 0.5-2.5%
Example of a moderate potency steroid
Betamethasone valerate 0.025% (betnovate RD)
Clobetasone butyrate 0.05% (eumovate)
Example of a potent steorid
Fluticasone propionate 0.05% (cutivate)
Betametasone valerate 0.1% (betnovate)
Betametasone dipropionate 0.05% (diprosone)
Example of a very potent steroid
Clobetasone proprionate 0.05% (dermovate)
Treatment of a plantar wart
Salicyclic acid 1-50% applied daily for 12 weeks
What is first line contraception for management of acne?
Microgynon
What is second line contraception for management of acne?
Dianette
Don’t continue once acne controlled for 3 months
Drugs that exacerbate psoriasis
Beta blockers Lithium Antimalarials NSAIDs ACE-I infliximab
What is a venous lake?
Angioma on the lip
No treatment needed unless wanted for cosmetic reasons
Skin disorders associated with SLE
Photosensitive ‘butterfly’ rash
Discoid lupus
Alopecia
Livedo recitularis
Investigations for allergic contact dermatitis
Patch testing
Causes of skin bullae
Epidermolysis bullosa (congenital) Bullous pemphigoid Pemphigus Insect bite Trauma/friction Furosemide Barbiturates
What is dermatitis artefacta?
Self inflicted skin lesions, patients deny that they are self induced
Features of dermatitis artefacta
Linear/geometric depending on cause
E.g. scratching, deodorant spray, inhaler
Appear suddenly
Commonly face or hands
Patients are non-chalant “la belle indifference”
What causes the itching in scabies?
Delayed type IV hypersensitivity reaction to mites laying eggs
30 days after initial infection
Scabies - features
Widespread pruritis
Linear burrows
In infants - face and scalp
1st line management for scabies
Permethrin 5%
2nd line management for scabies
Malathion 0.5%
Directions to give to patients about applying scabies treatment
Apply to all areas
Allow to dry for 8-12 hours for permethrin or 24 hours for malathion, then wash off
Repeat after 7 days
All of household treated
How long does pruritis last in scabies?
4-6 weeks after treatment
Causes of erythroderma
Eczema Psoriasis Drugs - e.g. gold Lymphoma, leukaemia Idiopathic